WO2019185218A1

WO2019185218A1 - Fuel distributor for internal combustion engines

Info

Publication number: WO2019185218A1
Application number: PCT/EP2019/052464
Authority: WO
Inventors: Klaus Joos; Alexander Schenck Zu Schweinsberg; Markus Amler; Michael Bauer
Original assignee: Robert Bosch Gmbh
Priority date: 2018-03-28
Filing date: 2019-02-01
Publication date: 2019-10-03
Also published as: KR20200135957A; DE102018204702A1; US20200340436A1; US11248572B2; CN111936737A; CN111936737B

Abstract

A fuel distributor (2), which serves in particular as a fuel distributor rail for mixture-compressing, applied-ignition internal combustion engines, comprises a main body (22), on which at least one high-pressure inlet (38) and multiple high-pressure outlets (24 - 26) are provided. Also provided is an insert body (15) which is arranged in an interior space (23) of the main body (22). Of the interior space (23), the insert body (15) at least substantially separates an inflow region (28), which extends from the high-pressure inlet (38) to the high-pressure outlets (24 - 26), from a clamping region (29). The insert body (15) is formed as a thin-walled insert body (15), which forms a partition (18) extending at least from the high-pressure inlet (38) to the high-pressure outlets (24 - 26) through the interior space (23).

Description

description

title

Fuel distributor for internal combustion engines

State of the art

The invention relates to a fuel distributor, in particular a fuel distributor strip for mixture-compressing, spark-ignited internal combustion engines. Specifically, the invention relates to the field of fuel injection systems of motor vehicles, in which there is a direct injection of fuel into the combustion chambers of an internal combustion engine.

From DE 10 2014 205 179 A1 is a fuel rail for a

Internal combustion engine known. The known fuel rail has an elongated housing with a cavity, a fuel flow into the cavity and at least two fuel outlets out of the cavity for each of a fuel injector. In this case, a body is arranged in the cavity, which has a groove which connects the two fuel outlets with each other, and in the region of the fuel inlet has a radially encircling groove around the body. The body with the two grooves serves as an insert, with which a direct inflow of the fuel from a pump to the injectors is ensured, which body can have an internal volume, which serves for damping, but is not in direct fuel flow.

The fuel rail known from DE 10 2014 205 179 A1 has the disadvantage that the insert is expensive to manufacture, since it is designed as a thick-walled tube with grooves. Furthermore, the known fuel rail is limited to a radial supply of the fuel, so that there is a limited scope.

Disclosure of the invention

The fuel distributor according to the invention with the features of claim 1 has the advantage that an improved design and operation are possible.

In particular, a cost-effective and / or easy to manufacture possibility be realized in order to realize an improved injection in combination with a good damping behavior.

The measures listed in the dependent claims are advantageous

Further developments of the fuel distributor specified in claim 1 possible.

The proposed fuel distributor is particularly suitable for the injection of a mixture, wherein the mixture composition should vary in operation. In particular, a direct water injection can be realized in the water in an emulsion with at least one fuel, in particular gasoline, in combustion chambers of a

Internal combustion engine is injected. Here, the water before or in a

High pressure pump fed to the fuel and along with this over the

Fuel distributor to be promoted to high-pressure injectors.

The composition of the mixture, in particular the emulsion, can vary during operation. For example, the addition of water may only be required or desired in a specific map area. For example, water or a larger proportion of water at high speed and / or high load may be desired. If this map area is left, for example in the case of an overrun fuel cutoff, then it is advantageous if the injected water content can be reduced rapidly and in particular quickly returns to zero. For this purpose, a short delay time between the addition of the water before or in the high-pressure pump and its injection via the high-pressure injection valves is required. The volume of the fuel distributor has in principle an increasing effect on this delay time. By dividing the interior of the body in an inflow area and a

Damping area, however, a shortening of the delay time at further existing damping, in particular damping of pressure pulsations possible. By the

Insertion body, the hydraulic volume between the high pressure input and the two or more high pressure outputs can be kept small, but a larger hydraulic damping volume can be realized.

The insert body is advantageously designed as a thin-walled insert body, resulting in low production costs. Here, a simple and cost-effective adaptation of a given high-pressure hydraulic system with respect to a realization of a direct water injection is possible. In this case, adaptation to different requirements, in particular a connection of the high-pressure line in a radial or axial manner, can furthermore take place if the base body is designed as a tubular basic body. Through the development according to claim 2, a division of the interior can be carried out in an advantageous manner. In this case, a connection to the damping region can take place outside the inflow region. Additionally or alternatively, it is possible in a development according to claim 3, that suitable passage openings are provided on the insert body in order to bind the inflow region at least locally to the damping region. Depending on the application, a damping behavior,

especially with regard to pressure pulsations. Especially in one embodiment of the main body as a tubular body can thereby when switching a fuel injector whose high-pressure outlet close to the

High-pressure input is located, resulting pressure pulsations may be effectively damped. Corresponding advantages arise in a development according to claim 4.

The development according to claim 5 has the advantage that a cost-effective and reliable attachment of the insert body in the body is possible. Additionally or alternatively, the development according to claim 6 has the advantage that an additional

Secured against displacement, in particular twisting, the insert body is realized during operation.

In a further development according to claim 7, if appropriate, a sufficient separation between the inflow region and the damping region can already be achieved by a geometric design of the insert body. The development according to claim 8 has the advantage that a small volume of the inflow area can be realized. Furthermore, disturbing influences by the insert body on, for example, the

Flow behavior in the inflow area can be minimized.

Advantageous possibilities for realizing an axial or radial high-pressure connection to the main body are specified in claims 9 and 10.

Brief description of the drawings

Preferred embodiments of the invention are described in the following description with reference to the accompanying drawings, in which corresponding

Elements are provided with matching reference numerals, explained in more detail. Show it: 1 shows a fuel injection system with a fuel distributor in a schematic representation according to a first embodiment of the invention.

FIG. 2 shows an insert body for the fuel distributor shown in FIG. 1 in a schematic, spatial representation; FIG.

3 shows a schematic section along the section line designated by III through the fuel distributor shown in Figure 1 according to a possible embodiment.

Fig. 4 is a partial, schematic sectional view of the in Fig. 1 with IV

designated section of the fuel distributor and

Fig. 5 shows the section shown in Fig. 3 by a fuel distributor according to a second embodiment.

Embodiments of the invention

Fig. 1 shows a fuel injection system 1 with a fuel distributor 2 in a schematic representation according to a first embodiment. In this embodiment, the fuel injection system 1, a fuel pump 3 and designed as a fore pump 4 metering unit 4. Furthermore, a high-pressure pump 5 is provided. The fuel pump 3 delivers liquid fuel from a tank 6 to the high pressure pump 5. The metering unit 4 serves for the temporary metering of water from a reservoir 7 in the funded fuel. The metering takes place in this embodiment in front of the high pressure pump 5. In a modified embodiment, the metering can also be done on the high pressure pump 5. Depending on the operating state, the liquid fuel or a mixture of the liquid fuel and water is then conveyed in a line section 8 provided between the fuel distributor 2 and the high-pressure pump 4. Here, the proportion of water in the mixture depending on the configuration may be fixed or vary in time.

The fuel distributor 2 is used for storing and distributing fuel

Fuel injection valves 9, 10, 1 1 and thereby reduces the pressure fluctuations or pulsations. The fuel distributor 2 may also serve to dampen pressure pulsations which may occur when switching the fuel injection valves 9 to 11. The fuel distributor 2 is designed such that, for example, when switching on or off the metering unit 4, a short delay time with respect to the addition of water before High pressure pump 5 and the injection of water through the fuel injectors 9 to 11 is reached.

FIG. 2 shows a loading body for the fuel distributor 2 shown in FIG. 1 in a schematic, spatial representation. Here, the insert body 15 based on a cylinder jacket-shaped basic shape 16, which is illustrated by broken lines. Starting from the cylinder jacket-shaped basic shape 16, a flattened side 17 is designed in this embodiment, on which a thin-walled partition wall 18 is formed. In particular, the entire cylinder jacket-shaped

Basic shape 16 be given thin-walled. The thin-walled partition 18 may be configured in particular cuboid. Furthermore, the insert body 15 has a recess 19 facing away from the flattened side 17, which divides the cylinder jacket-shaped basic shape 16 at the recess 19. This outer sides remain 20, 21, which are connected to each other in this embodiment, only for the thin-walled partition 18. The outer sides 20, 21 are geometrically preferably in the

cylinder shell-shaped basic shape 16. The outer sides 20, 21 are preferably thin-walled.

FIG. 3 shows a schematic section along the section line labeled III through the fuel distributor 2 shown in FIG. 1 according to a possible embodiment. The fuel distributor 2 has a base body 22 which is in this

Embodiment designed as a tubular body 22. In the main body 22, an inner space 23 of the fuel distributor 2 is formed. The insert body 15 is arranged in the assembled state in the inner space 23. Here, the flattened side 17 and the thin-walled partition 18 high-pressure outputs 24, 25, 26 for the

Fuel injection valves 9 to 11 facing, of which in Fig. 3 of the

High-pressure outlet 24 is shown. At the high pressure outlet 24, for example, designed as a cup 27 high-pressure port 27 is provided.

The insert body 15 divides the interior 23 into an inflow region 28 and a

Damping area 29 on. Here, the inflow region 28 and the damping region 29 are preferably connected to each other locally. In this exemplary embodiment, passage openings 30 are provided on the insert body 15 in the area of the high-pressure outlets 24 to 26, to which the inflow area 28 is connected locally to the damping area 29, wherein the passage opening 30 for the high-pressure outlet 25 is shown in FIG. Thus, in this exemplary embodiment, the dividing wall 18 formed by the insert body 15 separates the inflow region 28 from the damping region 29 in the inflow region 28 in a profile 32 considered perpendicular to a longitudinal axis 31 of the main body 22, whereby a connection via through-openings 30 is made possible. The inflow area

28 can thereby serve as an emulsion-conducting region 28 when the metering unit 4 is actuated. When metering water into the supplied fuel, the damping region 29 remains at least essentially a pure gasoline region 29. Thus, a large volume is available for pressure damping. As at the

Insert body 15 attack only the pressure differences by remaining pulsations, which are significantly lower than typical operating pressures, a thin-walled configuration of the insert body 15 is possible. In particular, the insert body 15 of a

thin-walled sheet metal are formed.

Preferably, the insert body 15 is formed so that it rests tightly and under tension on an inner wall 35 of the base body 22 of the fuel distributor 2. As an additional safeguard against rotation of the insert body 15 during operation, one or more connections 36 may be provided, at which the insert body 15 is at least locally connected to the inner wall 35 of the base body 22. Such connections 36 can be realized by welds 36 and / or welds 36 and / or, for example, by positive connections 36. This ensures that no high-pressure outlet 24 to 26 is closed or throttled inadmissibly.

The passage openings 30 can be realized for example by drilling, punching or the like. In addition or as an alternative, however, axial or radial distances between the insert body 15 and the inner wall 35 of the base body 22 may also be provided in a modified embodiment in order to provide a connection of the

Inflow region 28 to allow the damping region 29.

An advantageous separation between the inflow region 28 and the damping region

29 can also be achieved by the insert body 15 is formed so that it is arranged in the mounted state under a against the inner wall 35 of the body 22 applied bias in the interior 23. Specifically, the insert body 15 may be formed so that it at least largely rests against the inner wall 35 at least at the inflow region 28. For example, this can be realized via a section 37 which extends from a high-pressure inlet 38 to at least the high-pressure outlet 24 furthest from the high-pressure inlet 38.

In a modified embodiment, the insert body 15, for example, along the longitudinal axis 31 viewed only extend over the portion 37, the itself from the high pressure inlet 38 to the high pressure outputs 24 to 26 extending inflow region 28 pretends.

4 shows a partial, schematic sectional view of the section of the fuel distributor 2 designated IV in FIG. 1. In this exemplary embodiment, an end piece 41 is attached to one end 40 of the tubular base body 22. The end piece 41 has an eccentric fuel guide 42. In this way, a high-pressure port 43 can be arranged, for example, at least approximately on the longitudinal axis 31, while the high-pressure inlet 38 can be placed closer or close to the inner wall 35 of the main body 22. The eccentric

Fuel guide 42 and / or the high-pressure input 38 can in this case be designed so that a predetermined throttle effect is realized. For example, a cross-section, in particular diameter, of the eccentric fuel guide 42 and / or a cross-section, in particular a diameter, of the high-pressure inlet 38 can be executed at least in sections with a reduced diameter. Especially in combination with an eccentric fuel guide 42, a small volume of the inflow area 28 can be realized. As shown in Fig. 3, it is also advantageous for this, when an outer side 44, which faces the inflow region 28 in a part 45, in parts 46, 47 of the inner wall 35 of the base body 22 faces. This formation or bending of the insert body 15 enables a small volume of the inflow region 28 in combination with a stable and stable positioning in the main body 22.

FIG. 5 shows the section through a fuel distributor 2 shown in FIG. 3

according to a second embodiment. In this exemplary embodiment, a high-pressure port 43 is located at a wall location 48 of the base body 22 adjoining the damping region 29. Here, a fuel line 49 extending through the damping region 29 is provided which connects the high-pressure port 43 to a high-pressure inlet 38 of the inflow region 28. The fuel line 48 extends through the damping region 29, so that a radial arrangement of the

High-pressure port 43 to the tubular body 22 is possible. In this case, in the fuel line 49, a throttle 50 may be configured, which is the hydraulic

Vibration in the fuel line 49 attenuates. In this embodiment, the throttle 50 is provided at the high-pressure inlet 38.

The invention is not limited to the described embodiments.

Claims

claims

1. fuel distributor (2), in particular Brennstoffverteilerleiste for mixture-compressing spark-ignition internal combustion engines, with a base body (22) on which at least one high-pressure inlet (38) and a plurality of high pressure outputs (24 - 26) are provided, and at least one insert body (15) is arranged in an inner space (23) of the base body (22), wherein the insert body (15) of the inner space (23) extending from the high-pressure inlet (38) to the high pressure outputs (24 - 26)

Inflow region (28) at least substantially from a damping region (29) divides, characterized

in that the insert body (15) is formed at least essentially as a thin-walled insert body (15) which forms a partition wall (18) extending at least from the high-pressure inlet (38) to the high-pressure outlets (24-26) through the interior space (23).

2. Fuel distributor according to claim 1,

characterized,

in that the base body (22) is designed as a tubular basic body (22) and that the partition wall (18) formed by the insert body (15) in the inflow region (28) in a profile considered perpendicular to the longitudinal axis (31) of the base body (22) (32) considered the inflow region (28) at least partially separated from the damping region (29).

3. Fuel distributor according to claim 1 or 2,

characterized,

in that at least one through-opening (30) is provided on the insert body (15), to which the inflow region (28) is connected locally to the damping region (29).

4. Fuel distributor according to one of claims 1 to 3,

characterized,

in that the insert body (15) is arranged in the base body (22) such that at least locally a connection of the inflow region (28) to the damping region (29) takes place between an inner wall (35) of the base body (22) and the insert body (15) ,

5. Fuel distributor according to one of claims 1 to 4,

characterized,

in that the insert body (15) is shaped in such a way that the insert body (15) is arranged in the interior (23) of the main body (22) in the installed state under a pretension applied against an inner wall (35) of the main body (22).

6. Fuel distributor according to one of claims 1 to 5,

characterized,

in that the insert body (15) is connected at least locally to an inner wall (35) of the main body (22).

7. Fuel distributor according to one of claims 1 to 6,

characterized,

in that the insert body (15) is formed in such a way that the insert body (15) at least substantially abuts an inner wall (35) of the main body (22) at least at the inflow region (28).

8. fuel distributor according to claim 7,

characterized,

in that the insert body (15) has an outer side (44) on which the insert body (15) rests partially on the inner wall (35) of the main body (22), and / or in that the insert body (15) forms a part (45). the inflow region (28) facing

Outer side (44), wherein the insert body (15) in other parts (46, 47) of the outer side (44) on the inner wall (35) of the base body (22).

9. Fuel distributor according to one of claims 1 to 8,

characterized,

in that the base body (22) is designed as a tubular base body (22), in that a high-pressure connection (43) is attached to an end piece (41) provided at one end (40) of the tubular base body (22) and that in the end piece (41). an eccentric fuel guide (42) is formed to the high-pressure inlet (38) of the inflow region (28).

10. Fuel distributor according to one of claims 1 to 8,

characterized,

a high-pressure connection (43) is attached to a wall area (48) of the base body (22) adjacent to the damping area (29) and that extends through the damping area (29) and at least up to the insert body (15) Fuel line (49) is provided, which connects the high pressure port (43) with the high pressure input (38) of the inflow region (28).